Air/Fuel Mixture: Testing and Inspection

INSPECT CO/HC
(a) Set the vehicle to inspection mode.
(b) Start the engine.
(c) Run the engine at 2,500 rpm for approximately 180 seconds.
(d) Insert the CO/HC meter testing probe at least 40 cm (1.3 ft.) into the tailpipe during idling.
(e) Immediately check CO/HC concentration at idle and at 2,500 rpm.

HINT:
^ Complete the measurement within 3 minutes.
^ Check regulations and restrictions in your area when performing 2 mode CO/HC concentration testing (engine check at both idle speed and at 2,500 rpm).

(f) If the CO/HC concentration does not comply with regulations, troubleshoot in the order given below.
(1) Check A/F sensor operation.
(2) Check heated oxygen sensor operation.
(3) See the table below for possible causes, and then inspect and repair.